Computer networks are becoming increasingly important for businesses and communities. Cost efficiency, network capacity, scalability and flexibility are all important considerations in building and maintaining various networks. With a wide variety of services, protocols and technologies, it can be difficult to integrate and/or provide connectivity between different types of networks.
Virtual Private LAN Service (VPLS) is a way to provide Ethernet based multipoint to multipoint communication over IP/MPLS networks. VPLS allows geographically dispersed sites to share an Ethernet broadcast domain by connecting sites through pseudowires (PWs).
Ethernet Automatic Protection Switching (EAPS), offered by Extreme Networks of Santa Clara, Calif., is a solution for fault-tolerant networks. EAPS provides for a loop-free operation and a sub-second ring recovery. EAPS version 2 (EAPSv2) is configured and enabled to avoid the potential of super loops in environments where multiple EAPS domains share a common link. EAPSv2 functions use the concept of a “controller” and a “partner” mechanism. Shared port status is verified using health protocol data units (PDUs) exchanged by controller and partner. When a shared-link goes down, the configured controller will open only one segment port for each of the protected VLANs, keeping all other segment ports in a blocking state.
The Internet Engineering Task Force (IETF) RFC 4762, entitled “Virtual Private LAN Service (VPLS) Using Label Distribution Protocol (LDP) Signaling” proposes the use of redundant pseudowires (PWs) to attach to a VPLS core network. However, this technique is applicable only where a single attachment node is necessary. The IETF draft entitled “VPLS Interoperability with CE Bridges” also discusses redundant access to VPLS core networks. However, this technique does not address ring-based access networks and it utilizes only a single active attachment to a VPLS network. Likewise, the IETF draft entitled “Pseudowire (PW) Redundancy” discusses redundant access to VPLS core networks, but fails to address ring-based access networks and only utilizes a single active attachment to a VPLS core network.